The present invention relates to a signboard structure, and more particularly to a structure for quickly and detachably assembling a face panel to a case of a signboard. A plurality of light emitting elements are arranged on a back panel of the case to partially expose from a plurality of through holes correspondingly provided on the face panel. Magnetic elements are correspondingly provided on the case and a rear side of the face panel at predetermined positions, so that the face panel is quickly and detachably assembled to the case by means of magnetic adherence to show different static pictures and/or texts painted on the face panel.
Most currently available electronic signboards generally include a big-size panel having a plurality of controllable light emitting elements provided at a front surface thereof. The light emitting elements are electrically connected to emit light via control of various circuits, so as to present desired pictures or texts on the front surface of the panel. Such signboards are usually mounted at high places, such as the front of high-rise buildings located at main road intersections.
However, the light emitting elements for such electronic signboards are directly exposed to external environments. There are not dustproof, wind-tight or watertight structures provided with the signboards to protect the light emitting elements, resulting in a high rate of failure of the light emitting elements. Moreover, light emitted from the light emitting elements on the electronic signboards under the sun is setoff by the sun light, resulting in an inferior visual effect of the signboards.
A second type of very popular advertising signboard is the canvas signboard that provides completely fixed or static pictures and/or texts without any change. Moreover, additional spotlights are needed to illuminate the canvas signboard in the nighttime.
A third type of signboard is the movable signboard that includes a plurality of parallel and turnable bars arranged side by side. Each of these bars has a triangular cross section and therefore has three sides. When all the triangular bars are turned to show the first side thereof, a first static picture or text is presented. And, when the bars are turned to show the second or the third side thereof, another two different static pictures or texts may be selectively presented. That is, the movable signboard can only sequentially present up to three static pictures or texts one by one, and is therefore not so changeful and attractive as compared with the electronic signboard. Moreover, the movable signboard also needs additional spotlights to illuminate the pictures and texts in the nighttime.
A fourth type of signboard is the neon signboard that also provides only limited numbers of changeable pictures and texts and is therefore not so attractive as the electronic signboard. At best it provides changeful pictures and texts in a way similar to revolving lanterns.
In Taiwan Patent application No. 89218561 entitled xe2x80x9cSignboardxe2x80x9d, which is filed by the same inventor of the present invention, there is disclosed an improved signboard structure in an attempt to eliminate the drawbacks existed in the above-mentioned various types of signboards. FIGS. 1 and 2 are assembled sectional view and exploded perspective view, respectively, of the signboard disclosed in Taiwan Patent application No. 89218561. As shown, the signboard includes a case 3 having a back panel 30 and four sidewalls 31 to define a front opening, a plurality of light emitting elements 2 densely arranged on the back panel 30 with a sealing material 5 applied to seal a space between a base portion of the light emitting elements 2 and an inner side of the back panel 30 to prevent moistures and/or dust from penetrating into the base portion of the light emitting elements 2, a face panel 4 mounted to the front opening of the case 3 and provided with a plurality of through holes 41 corresponding to the light emitting elements 2 arranged on the back panel 30 for the light emitting elements 2 to partially expose from the through holes 41. Areas on the face panel 4 that are not provided with through holes 41 may be painted with static pictures or texts, so that these pictures or texts could be clearly seen in the daytime. In the nighttime, the light emitting elements 2 are lighted under control of circuits to present other dynamic pictures or texts on the face panel 4, so that the signboard functions as a television wall or an electronic signboard and is industrially practical for use.
However, it is desirable the face panel of the signboard with static pictures or texts could be securely and detachably mounted to the front opening of the case 3 in an easy and quick manner without the risk of separating from the case, in order to conveniently replace the face panel to show other static pictures and texts.
A primary object of the present invention is to provide a signboard structure that allows easy, quick, secure, and detachable mounting of a face panel painted with static pictures and texts to a case of the signboard.
Another object of the present invention is to provide a signboard structure that includes a case being provided on a back panel thereof at positions that are not provided with light emitting elements with a plurality of magnetically permeable boxes, in each of which a magnetic elements is sealed with a sealing material applied into the case, such that the magnetic elements are isolated from external environments to well maintain their magnetism to always stably magnetically hold a face panel to the case.